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Overheating(what's the problem?)

jerry16jerry16 Member Posts: 22
edited March 2014 in Pontiac
My Firebird "shut itself off" a couple of days
ago. I was about 5 minutes from home when the
check gages indicator came on. I tried to get home
but as I was turning the corner the car just shut
itself down. I noticed that about the same time
the gages light came on my heater started blowing
cold air out( it was on the hottest setting!). The
coolant level was fine, could it be the
thermostat? Anyone have any ideas? Help! -J
«1

Comments

  • KCRamKCRam Member Posts: 3,516
    Sounds like your water pump died. That would explain your coolant level being okay and the cold air in the heater vents. No water was circulating through the engine or the heater core. The engine computer is designed to make these shutdowns when the engine temperature exceeds a point where coolant will no longer be effective, thus all your dashboard warnings.
  • gchernya1gchernya1 Member Posts: 43
    You lost vaccum pal, this is the cause of all of it. Your directors in Heater/AC is powered by engine vaccum. Broken vaccum hose may be the reason as well as more expensive things like any vaccum powered divice, some of them deep under dush.
  • bigfur1bigfur1 Member Posts: 34
    Could be the thermo also.
  • quadrunner500quadrunner500 Member Posts: 2,721
    Which engine in the Firebird? Was it the coolant level in the overflow tank you were looking at, or was there coolant in the radiator itself? Check the belts?
  • KCRamKCRam Member Posts: 3,516
    regarding what gcher said,

    If it was a vacuum loss, the power steering would have stopped, not just the heat - that's vacuum-assisted as well. Jerry would have noticed he went to manual steering along with everything else. His original complaint was overheating and an automatic engine shutdown, not simply his heater cutting out.
  • jerry16jerry16 Member Posts: 22
    kcram gcher:

    Thank you both. The power steering DID in fact go out. I didn't mention it because I though the switch to manual steering was a product of the car shutting itself off. I had no idea it could be related to the vacuum. And also, the car never smoked or anything, I just noticed the temp gauge went into the red and the check gauges light came on. I assumed it shut down before overheating. The coolant level was checked in the radiator and the overflow. Matter of fact, I loosened the cap on the radiator to listen for water and sure enough the coolant slushed around violenty.( NOTICE: DO NOT EVER REMOVE THE CAP WHILE THE ENGINE IS HOT), I swear the coolant would've shot twenty feet into the air. With this info, is it definitly the vac? How do I go about fixing it? I will be trading this car in for a v8 soon and hope it's not too expensive!
  • KCRamKCRam Member Posts: 3,516
    Jerry,

    Since your steering did die, then I do concur with gcher that you probably have a vac leak somewhere. A competent mechanic should be able to do a vacuum test and find it pretty easily. (Good call, gcher!)

    If it's just a hose as gcher surmised, the job is somewhat similar to fixing a radiator hose. If they can't find a specific leak, then they will test the engine's ability to produce vacuum.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    So wait a minute...why would this car overheat due to a vacuum leak....don't get that part....
  • quadrunner500quadrunner500 Member Posts: 2,721
    You cannot check the coolant level by listening for the sound of fluid gushing with your ear, when it is hot. Check it again cold, in the radiator. Observe the level of the fluid. It may be very low on coolant. What about the radiator cooling fan switch? Do you hear the fans coming on? Have you tried reading-out the "service engine soon" code? If the engine died, you would lose power steering and vacuum. Did you lose power steering before it died? What about the belt?
  • KCRamKCRam Member Posts: 3,516
    Shift,

    from Jerry's symptoms, it sounds as if he may have lost water pump pressure and in the "struggle" took out the vacuum hose to the HVAC as gcher mentioned (since the coolant was not flowing properly through the system). He did say he lost everything when the Check Gauges light came on, and he tried to make it home - before he made it, the engine went to the failsafe shutdown.

    Without examining the Firebird, of course, we are all making educated guesses based on experience, but it sounds like a combination of some type of coolant flow failure and a possible resulting vac leak.
  • jerry16jerry16 Member Posts: 22
    Here is exactly what happened:

    Check gauges light came on, at about the same time cold air started blowing out of the vents( it was on hot)

    I tried to make it home (about five minutes away)

    About 1 minute from home while turning the corner the car shut down. AFTER the car shut down, I lost power steering.

    I sat for about five minutes to see if it would cool down. The gauge never moved so I popped the hood, there was no smoke or burning smell. I loosened the cap on the radiator and the coolant went crazy(don't know what that means). Called my wife and asked her to bring me some coolant.

    Wife brought the coolant, I put it in the overflow tank.

    Waited about ten more minutes started the car and drove 1 minute home.

    I hope that clarifies everything. I appreciate you guys helping me out. -j
  • KCRamKCRam Member Posts: 3,516
    Jerry,

    ok, that's a little different. Your power steering stopped because the engine wasn't running - I thought you lost it while driving.

    Somewhere between the water pump and the HVAC, you lost coolant flow. It's either a failure (vacuum or otherwise) in the HVAC area, or there is some kind of blockage in a coolant line.

    Did you happen to hear an unusual "clunk" or "hiss" just before the warning light came on and the cold air started? When you restarted and got home, did you happen to listen under the hood with the engine running when you got home? If you haven't yet, give it a shot and see if you hear a hiss or whistle that would be indicative of an air/vacuum leak.
  • quadrunner500quadrunner500 Member Posts: 2,721
    If it didn't throw a belt operating the water pump, then it sounds like it just ran out of coolant. And you can't just put it back into the overflow tank when it really runs out. You have to let it cool, and put it into the radiator itself. The coolant overflow recovery tank can be full...but the radiator and block empty! Now if that's the case, you have to find out why it lost the coolant. A pressure test can reveal this. Coolant can leak out of a hose, but these days it's more likely it's dripping out of the water pump because of an aged seal. A radiator cap can also leak.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Yeah, he's right, if you're low on coolant, it went somewhere...also, the fact that the heater blew cold is another good sign of low coolant level...pressure test should turn up something here.
  • bcathcartbcathcart Member Posts: 54
    A common problem often missed is blockage of the radiator fins by insects.When the car cools all the usual tests show up ok.A good blast through from rear to front with an airline or water jet can often transform a radiator performance.Surprisingly this simple job is often missed even by experienced mechanics.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Very good point but this wouldn't explain his symptoms directly in this particular case...from what I'm reading, he lost coolant with no apparent leak...that can only mean one thing (gulp)...is it being burned?
  • bcathcartbcathcart Member Posts: 54
    Could have blown out rad cap at 13 psi and at 110c would evaporate instantly at atmospheric pressure,steam would not always be apparent dependant on local air temp.Fill the rad at night and check the dipstick in the morning for water droplets if burning off is suspected.I am told by old guys that water injection improves performance so it's not all bad.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Yes, but anti-freeze lubrication of engine bearings needs further development to be successful..:)

    But...but...radiator cap wouldn't pop-off on a modern system...it should go into the overflow, shouldn't it?
  • rlhandrlhand Member Posts: 1
    Little late in the game here but noone seems to have asked the question if possibly the radiator could have started out being froze which would have resulted in water loss. Since you apparently had the heater on max it must have been cold outside. Just another thought....
  • jerry16jerry16 Member Posts: 22
    Everyone, thanx for the help. Checked the fluid level and, low and behold, it was looooow. Filled it and the car so far has been great. (replaced my thermostat while I was at it). Apparently, it leaked over a long period through the cap and evaporated into the air. I took it to a mechanic to check it and that is what he said. He also said that many times if a car is burning coolant it will have a distinctive smell to it?! Anyone heard of that before? Well, for now I will enjoy driving as everything seems OK.
  • KCRamKCRam Member Posts: 3,516
    Jerry,

    Your mech is right - burning coolant smells awful - you'd know it in a second...

    Glad to hear it wasn't as bad as it could have been.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Yes, the smell is bad unless it's just a tiny leak then you might not notice...I'd keep a close eye on the fluid level...if it goes down again, you need to apply some agressive diagnostics...I presume your mechanic pointed to evidence of this leak? A stain down the radiator or crystalline residue of some sort? If your radiator around the cap is spanking clean and shiny, he didn't solve the problem, IMO...excuse me if I don't let you off the hook...when it comes to fixing cars, I am relentlessly skeptical and this seems to help.
  • spokanespokane Member Posts: 514
    Good advice from Shiftright. I believe the "odor check" can also often be used to detect a coolant leak to a combustion chamber, as with a head gasket failure or cracked head, even if the leak is as little as one or two pints per 1000-miles.

    This odor (burner ethylene glycol) is similar to that of burned polyethylene. Try burning a little of the insulation from a piece of automotive wiring to familiarize yourself with the odor.

    Get the suspect car up to full operating temperature and then park it in a closed garage. Wait 2 or 3 minutes and check for the odor. If the odor is present, assuming there are no hot electrical components or polymer on the hot exhaust system components, it's probably time to pull the cylinder head.

    In order to have adequate "odor sensitivity", it's probably best if one person warms up the car and another second person makes the "odor check."

    Has anyone else used this criteria? Your comments?
  • guitarzanguitarzan Member Posts: 873
    Sorry Spokane, that is pretty irresponsible advocating running an automobile in a closed garage. THIS IS VERY DANGEROUS.
  • spokanespokane Member Posts: 514
    Agreed, you need not run the engine in a closed garage. Stop the engine when you close the garage door. I have found that the hot engine and exhaust system, after a few minutes parked in an area with no air circulation, may emit the distinctive odor to show the presence of coolant in a combustion chamber. There may be some instances in which there is damage but no odor; so this method is not a certain diagnosis.

    Sorry that post #23 was incomplete.
  • gusgus Member Posts: 254
    Good to clarify it, thanks spokane.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Also, if I might be a bit macabre, cars today are running so damn clean you'd have to be very patient to kill yourself...nonetheless...SAFETY FIRST!
  • gusgus Member Posts: 254
    That's right!! You'd get a bad headache, but you probably wouldn't die (nevertheless, don't test this out)!
  • app1nagapp1nag Member Posts: 15
    A few months back I installed a radiator for my 1989 Dodge Caravan 4 cyl non-turbo engine. After installation the coolant level remained constant and the temperature level never exceeded normal level.

    However, a few weeks ago I noticed that I was low on coolant and added some. I've been checking every day since then and I need to add coolant practically daily. I do not see any leaks nor is there ever any coolant on the ground under the vehicle. The car runs cool enough when I am moving but when I stop (at a traffic light, for example) the temperature starts to climb. Once I get moving again the needle moves back to an acceptable temperature range. When I arrive at my
    destination and exit the vehicle I can smell a strong odor of coolant from the engine compartment. The hoses and radiator cap are extremely hot and there is a lot of pressure built up.

    I've tried numerous things to correct the situation such as:

    1) replacing the radiator cap with a 'pressure- release' cap...whenever I park the car and release the pressure by lifting up the little
    handle on the cap, coolant flows in to the overflow bottle and it is actually boiling hot.

    2) flushed the entire system, and added fresh coolant/water mix.

    3) replaced the thermostat.

    4) verified the fan and water pump are functioning.

    I'm stumped and was wondering what could possibly cause the vehicle to run so hot while losing coolant daily? And why am I not seeing any
    coolant on the driveway?? Could the coolant be evaporating due to the intense heat? Would a cooler thermostat help? Could there be something
    wrong with the radiator? Any advice would be appreciated!

    Thanks!
  • spokanespokane Member Posts: 514
    App1nag, you seem to have done all right things. While you have verified that the fan functions, your symptoms still point strongly toward the fan, fan relay, and fan thermostatic switch. If there's any doubt, a replacement thermo switch and relay would be worthwhile at $20 - $35 plus installation. Wiring in this area can also be deteriorated; wiggle the wiring and connectors to and fro with the fan running to check for an intermittent open circuit.

    As to the loss of coolant, the head gasket on the 2.5 liter Chrysler engine is somewhat prone to failure. The failure is usually at the end of the head and coolant leaks into either #1 or #4 cylinder. The leakage rate could be little enough that driveability is OK but coolant is disappearing.

    I would first concentrate on the fan-related items. Hopefully, the disappearing coolant is a hose leak ...and you don't see it because the high temperature evaporates it before it drips on the pavement. Hopefully, after the high temp problem is resolved, you will find just such a leak rather than having to remove the cylinder head.

    A cooler thermostat won't help. I would change the thermostat (using the reccommended temp setting) only if the problems started shortly after installation of the present thermostat.
  • app1nagapp1nag Member Posts: 15
    Wow...that was a fast reply...thanks for the info on the hot Caravan....do you know if replacing the thermo switch and relay is a difficult procedure? It appears you feel that these are two distinct problems: one being the overheating and the other being the coolant loss.
  • gchernya1gchernya1 Member Posts: 43
    I've met situation when overheating was caused by sleeping belt, that in it's turn did it because a high rolling resistance of one of the components engaged through this belt. As a preventive measure I shortened fan relay to make it start a fan together with ignition on. It helped somewhat, until real problem - faulty tensioner, pronounce itself clear enough. You can try this approach as cheep alternative to above mentioned replacements. Sure, warm up will take little longer with fan on, but this is not a problem at this point.
  • ratchratch Member Posts: 21
    Some bits of wit when overheating happens:

    Low/no coolant. No or intermittent heat from heater.

    Coolant, but...
    temperature climbs going down the road -- poor circulation through radiator -- (1) clogged radiator (2) water pump/belt problem (3) collapsing suction side radiator hose -- very rare.

    temperature climbs while stopped on idle -- normal until fans kick in. If it still climbs -- (1) bad thermostat (2) clogged radiator -- inside or out (3) water pump/belt problem.

    Hot engine, coolant overflowing and blowing -- (1) bad thermostat (2) slipping water pump belt (3) slipping water pump impeller.

    Hot engine, no overflow or only steam -- low/no coolant.

    Thermostats can be checked. Put a candy thermometer in radiator with cap off (on cars which can be run with an open system). Observe coolant temp when circulation starts.

    If engine won't normalize (modern high efficiency), remove thermostat from cold engine, test in a pan of water with a candy thermometer. Look on thermostat for temp range. Most start opening just before water boils, some just after if at high altitude. Bad ones either don't open or open very little in boiling water.

    Bad thermostats can be intermittent.

    Test new thermostats before installing -- I have had three bad thermostats right out of the package.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    ah, the golden rule of good diagnostics...never assume a new part is a good part.
  • ChingCChingC Member Posts: 11
    If coolant disappear in a small amount randomly, not regularly, and there is no leaking in the system, what could be the problems; head gasket leaking, cracking, belt slipping, ???, and what will be the suggested remedies?
    Thanks for the advise.
  • spokanespokane Member Posts: 514
    Random loss of coolant, with no apparent external leakage, is not likely to be associated with a slipping drive belt. It could be a head gasket or cracked head, but if the car otherwise runs OK and you have no odor of burned ethylene glycol, it's suggested you look further for leakage.

    The coolant pump will sometimes leak during running but not leak when stopped ...so you don't see any coolant on your garage floor. Look carefully at the weep hole on the bottom of the pump housing; you may need a flashlight and small mirror to be able to see it. A small amount of residue at the weep hole is normal but if you see coolant drooling out, replace the pump. Careful checks of the radiator and all hose connections may also reveal residue that indicates a leak which evaporates rapidly such you you don't find drippage on the garage floor. Also check the heater housing and carpeting beneath the heater to see if the heater is leaking.

    Hopefully, your problem is some type of external leak rather than an internal engine problem.
  • ChingCChingC Member Posts: 11
    to spokane

    Thanks for your quick response and suggestion. It makes sense. However, I still can not locate any obvious leak. If it is the head gasket, can the head be re-torqued, so that the gasket is sealed to stop the possible leak? Of course, it is not going to work if the head is cracked. But, what is the risk to re-torque the head if the manufacturer's procedures is followed? Is there any test that can be done to pin point the problems associated with head, such as gasket or cracked head?
  • spokanespokane Member Posts: 514
    Good question, ChingC, on re-torqueing the head. My experience is that once a head gasket has begun to leak, it is very unlikely that re-torqueing will enable it to re-seal. However, it can't hurt to retorque if you follow manufacturer's spec as to bolt sequence and torque level.

    Pleas note the above posts 21-26 regarding the odor that usually accompanies a coolant leak into a combustion chamber.

    Another check: If coolant is getting into a combustion chamber, sometimes the coolant's green-yellow color can be seen baked into the residue on the spark plug. Remove the plugs and inspect them carefully. This is not a certain test; it's possible to have such a leak and not find the green-yellow residue.

    If the engine is performing OK and you don't have the above symptoms of an internal leak, I would not remove the cylinder head until I had a careful inspection done by someone well qualified in solving cooling system problems.

    What kind of engine do you have? Please let us know what you find.
  • ChingCChingC Member Posts: 11
    Thanks again. I will check the spark plugs carefully. Mine is 87 Mbz 300E about 100K mile.(bought used at 75K miles) It is a great car, however, there are lots of minor nuisances and repairs, etc.

    I have been talking to several mechanics, about the possible causes of the coolant loss. And, so far, I haven't find someone that I feel comfortable to turn the car in yet. Beside, it is a minor leak/loss at this point. Mbz uses a colorless ethylene glycol solution, therefore, the baked color may not be there. But, I will try to find out myself when I got a chance. One auto part store suggests a kind fluid to be added to the coolant. Under the timing gun light, you will see a different "light/color" at where the coolant leaks. It sounds pretty good, however, I havn't have guz to try it yet.

    So far, I did not smell the odor of the burned ethylene glycol as discussed.
  • Mr_ShiftrightMr_Shiftright Member Posts: 64,481
    Has the cooling system been pressure tested yet?
  • ChingCChingC Member Posts: 11
    Two pressure tests done by two mechanics can not locate any leak.

    When the car is idling at intersection in hot days (outside air at 85 deg C), I can see the water temperature goes up from approximately 70 to 85 deg C. Coincidentally, more water is consumed at 85 deg C. I guess that at a higher water temperature/pressure, it leaks more. I need to add 10 oz water or so in a hot week. I did not have chance yet to hear a third opinion, but plan to do so in about 3-4 weeks.
  • spokanespokane Member Posts: 514
    You are surely correct in your observation that most causes of coolant loss would associate a higher loss rate with higher pressure/temperature. However, your temperature information is curious. I don't know the exact Mercedes specification, but a temperature of 70C is rather low. I would expect the temp to range between about 92C and 106C, depending on load, speed, and electric fan cycling. It seems that your temperature readings are incorrect or you thermostat is defective. A too-low operating temperature contributes to excessive engine wear.

    However, ChingC, a low-temperature coolant problem does not explain the coolant loss which is the basis of your concern.
  • ChingCChingC Member Posts: 11
    The temperature readings are from the gage in the panel. It is not calibrated and may not be correct. However, the Mbz is equipped with an inductive type engine driven mechanical fan at a low rpm. This may explain why the normal coolant temperature is low, around 75C. I could not find any normal temperature spec from the Service Manual. I tried to idle the engine to allow kicking in the electrical driven auxillary fan. The auxillary fan shall be kicked in at coolant temperature of 110C, however, I can not get the coolant temperature up to there.

    Anyhow, I am talking to another Mbz mechanic. He mentions that the Mbz's engine freeze plugs are cheap gage metal made instead of brass type, and therefore, it may leak due to corrosion. There shall be white residue around the leaking places. He pretty much agrees with you on the other possible visible spots for the causes, such as circulating pump drain hole, radiator drains, etc.

    As for the coolant burning smell at the exhaust, he feels that one may not be able to smell anything for a small coolant consumption.

    What shall be done on the car? His suggestion is that all "external" related cooling loss causes, such as freeze plug, radiator, circulating pumps, etc. must be ruled out first, say, with 95% certainty, before considering the head job, which is an expansive "internal" problem, $1000-1300. The alternate option is to keep on driving until the problem gets worse. Then, you know for sure that it is a head problem, assuming there are no other visible "external" problems. Anyway, I am planning to have him check it up, and the tentative appointment is set approximately two weeks from now.
  • spokanespokane Member Posts: 514
    I agree with your mechanic's comments. Even though he has not yet clearly identified the coolant-loss problem, I believe he's on the right track. I am not familiar with the colorless anti-freeze solutions; you may want to ask him about the possible use of Prestone brand antifreeze or some tracer additive that M-B recommends. As he suggests, you certainly do want to investigate all possible external leak sources thoroughly before considering cylinder head removal.

    As to temperature, I expect you do not have a problem because the dashboard gauge is often just a rough indicator. You could attach a thermocouple to the hot water outlet, cover it with insulation, and compare the readings with the dashboard gauge. You could then place a piece of cardboard in front of the radiator; this would force the temperature to 110+C even with the inductive primary fan running and provide a check of the secondary fan operation. If you don't have an accurate independent temperature device such as the thermocouple, however, you risk overheating with the "cardboard" procedure. In that case, ask the shop to do a temperature and auxiliary fan check.
  • ChingCChingC Member Posts: 11
    Thanks for the suggestion. Mbz's cooling system is not "typical". In other words, there is no cap on the radiator. The overflow tank appears to be part of the system. I suspect that it is a "semi-closed" system, i.e. the operating pressure is somewhat higher than usual. I have no clue though. As for the thermocouple option, it may not work, because the cooling water pressure will exceed one atmospheric at a temperatue exceeding 100 C. In other words, water will splash out of the tank if it is not capped, and I am quite sure to make it safe with a thermocouple.
  • tedjonestedjones Member Posts: 1
    the cars' temp. guage has been going up and down on the highway. Now it goes up and overheats. The thermostat has been replaced several times and it has been to the Pontiac garage. They can not find the problem. Can anyone help?
  • carmikecarmike Member Posts: 1
    I have a 1994 Toyota Corolla which has undergone regular maintenance checks and has had oil and fluids checked every 3,000 miles. Last Sunday after driving it for 15 minutes white smoke started spewing out of the engine and the engine light went on. Now the car is in the shop to the tune of $4,000.00 for a new/re-built engine and a new radiator, etc. Has anyone ever had this happen to them? What could the cause have been? Thanks, enginewoes
  • bobs5bobs5 Member Posts: 557
    Sounds like a head gasket went bad and coolent is now getting into a cylinder of the engine.
    We had a 1979 Datsun 310 which the headgasket went bad on. Lots of white smoke!
  • boeingboeing Member Posts: 1
    About 1 year ago, the radiator on my 1991 Lexus ES250 was leaking and couldn't be fixed. I replaced the radiator with an after-market product. The radiator cap was different from the original and I didn't know it. I drove it until recently when the coolant started spilling out through the overflow tank on a regular basis. The dealer replaced one hose and identified the problem with the radiator cap. I replaced the cap with one that seems to fit right and coolant stopped being lost through the overflow. The problem now is that I have to top off the coolant in the radiator each morning.
    There is a slight smell of coolant in the car when the windows are closed but I don't see any leaks. Any ideas?
    By the way, the overheating problem only started happening when I brought my car to the dealer about a month ago. The engine was idling rough and I was told that my spark plug wires, distributor cap and rotor needed changing. I had them do this work along with replacing the spark plugs. Is it possible that the mechanic forgot to attach a hose or something that would cause me these problems?
    Please let me know. Thank you.
  • spokanespokane Member Posts: 514
    Boeing, I believe you are on the right track. Since you don't see any leaks but must add coolant regularly, it's likely that a heater hose was loosened and the leakage is on the inside of the firewall ...thus the coolant odor inside the car. A failed heater core is possible but is less likely than a leaking connection under the circumstances you describe. Pull the carpet away from the floorboard to check for dampness. I expect you have a drying out job to do as well as replacement/reconnection of the heater hose. Good luck; let us know what you find.
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